EEdukron DevOps Library
NetworkingFoundation15 submodules

Networking Fundamentals

Understand how application traffic moves from a client through name resolution, routing, security controls, proxies, load balancers, and transport sessions to a service endpoint.

How this module works

From concept to production evidence

Troubleshoot by following the packet path layer by layer: resolve the name, identify addresses and routes, test ports and transport, validate TLS, then inspect HTTP behavior.

Learning outcomes

  • Explain OSI and TCP/IP responsibilities
  • Calculate subnets and CIDR ranges
  • Trace DNS, routing, NAT, and load-balancing paths
  • Differentiate TCP, UDP, HTTP, and HTTPS behavior
  • Diagnose firewall, proxy, and certificate failures

Flow diagram

Networking Fundamentals end-to-end flow

Use this sequence as the operating backbone for every submodule note and hands-on exercise.

  1. 01
    Resolve nameNetworking Fundamentals stage 1: resolve name with an auditable result before the next stage begins.
  2. 02
    Select routeNetworking Fundamentals stage 2: select route with an auditable result before the next stage begins.
  3. 03
    Apply NAT and firewallNetworking Fundamentals stage 3: apply nat and firewall with an auditable result before the next stage begins.
  4. 04
    Establish transportNetworking Fundamentals stage 4: establish transport with an auditable result before the next stage begins.
  5. 05
    Negotiate TLSNetworking Fundamentals stage 5: negotiate tls with an auditable result before the next stage begins.
  6. 06
    Serve application requestNetworking Fundamentals stage 6: serve application request with an auditable result before the next stage begins.

Integrated hands-on lab

Trace an HTTPS request end to end

  1. Resolve the hostname
  2. Inspect subnet and route selection
  3. Validate firewall and port access
  4. Inspect the TLS certificate
  5. Trace proxy and load-balancer forwarding

Complete module contents

15 full submodule notes

Read in order
01

OSI & TCP/IP

OSI & TCP/IP governs how a request is named, addressed, routed, filtered, transported, protected, and delivered to a healthy endpoint within Networking Fundamentals. It is not an isolated definition: its value appears when it supports troubleshoot by following the packet path layer by layer: resolve the name, identify addresses and routes, test ports and transport, validate TLS, then inspect HTTP behavior.

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02

IP addressing

IP addressing governs how a request is named, addressed, routed, filtered, transported, protected, and delivered to a healthy endpoint within Networking Fundamentals. It is not an isolated definition: its value appears when it supports troubleshoot by following the packet path layer by layer: resolve the name, identify addresses and routes, test ports and transport, validate TLS, then inspect HTTP behavior.

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03

Subnets

Subnets governs how a request is named, addressed, routed, filtered, transported, protected, and delivered to a healthy endpoint within Networking Fundamentals. It is not an isolated definition: its value appears when it supports troubleshoot by following the packet path layer by layer: resolve the name, identify addresses and routes, test ports and transport, validate TLS, then inspect HTTP behavior.

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04

CIDR

CIDR governs how a request is named, addressed, routed, filtered, transported, protected, and delivered to a healthy endpoint within Networking Fundamentals. It is not an isolated definition: its value appears when it supports troubleshoot by following the packet path layer by layer: resolve the name, identify addresses and routes, test ports and transport, validate TLS, then inspect HTTP behavior.

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05

DNS

DNS governs how a request is named, addressed, routed, filtered, transported, protected, and delivered to a healthy endpoint within Networking Fundamentals. It is not an isolated definition: its value appears when it supports troubleshoot by following the packet path layer by layer: resolve the name, identify addresses and routes, test ports and transport, validate TLS, then inspect HTTP behavior.

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06

DHCP

DHCP governs how a request is named, addressed, routed, filtered, transported, protected, and delivered to a healthy endpoint within Networking Fundamentals. It is not an isolated definition: its value appears when it supports troubleshoot by following the packet path layer by layer: resolve the name, identify addresses and routes, test ports and transport, validate TLS, then inspect HTTP behavior.

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07

HTTP/HTTPS

HTTP/HTTPS governs how a request is named, addressed, routed, filtered, transported, protected, and delivered to a healthy endpoint within Networking Fundamentals. It is not an isolated definition: its value appears when it supports troubleshoot by following the packet path layer by layer: resolve the name, identify addresses and routes, test ports and transport, validate TLS, then inspect HTTP behavior.

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08

TCP/UDP

TCP/UDP governs how a request is named, addressed, routed, filtered, transported, protected, and delivered to a healthy endpoint within Networking Fundamentals. It is not an isolated definition: its value appears when it supports troubleshoot by following the packet path layer by layer: resolve the name, identify addresses and routes, test ports and transport, validate TLS, then inspect HTTP behavior.

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09

Ports

Ports governs how a request is named, addressed, routed, filtered, transported, protected, and delivered to a healthy endpoint within Networking Fundamentals. It is not an isolated definition: its value appears when it supports troubleshoot by following the packet path layer by layer: resolve the name, identify addresses and routes, test ports and transport, validate TLS, then inspect HTTP behavior.

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10

Routing

Routing provides a concrete platform capability that must be configured, secured, validated, observed, and owned throughout its lifecycle within Networking Fundamentals. It is not an isolated definition: its value appears when it supports troubleshoot by following the packet path layer by layer: resolve the name, identify addresses and routes, test ports and transport, validate TLS, then inspect HTTP behavior.

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11

NAT

NAT governs how a request is named, addressed, routed, filtered, transported, protected, and delivered to a healthy endpoint within Networking Fundamentals. It is not an isolated definition: its value appears when it supports troubleshoot by following the packet path layer by layer: resolve the name, identify addresses and routes, test ports and transport, validate TLS, then inspect HTTP behavior.

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12

Load balancing

Load balancing governs how a request is named, addressed, routed, filtered, transported, protected, and delivered to a healthy endpoint within Networking Fundamentals. It is not an isolated definition: its value appears when it supports troubleshoot by following the packet path layer by layer: resolve the name, identify addresses and routes, test ports and transport, validate TLS, then inspect HTTP behavior.

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13

Firewalls

Firewalls controls which actor may perform which action on which resource, under which conditions, with evidence that can be reviewed later within Networking Fundamentals. It is not an isolated definition: its value appears when it supports troubleshoot by following the packet path layer by layer: resolve the name, identify addresses and routes, test ports and transport, validate TLS, then inspect HTTP behavior.

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14

SSL/TLS

SSL/TLS provides a concrete platform capability that must be configured, secured, validated, observed, and owned throughout its lifecycle within Networking Fundamentals. It is not an isolated definition: its value appears when it supports troubleshoot by following the packet path layer by layer: resolve the name, identify addresses and routes, test ports and transport, validate TLS, then inspect HTTP behavior.

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15

Proxy & reverse proxy

Proxy & reverse proxy governs how a request is named, addressed, routed, filtered, transported, protected, and delivered to a healthy endpoint within Networking Fundamentals. It is not an isolated definition: its value appears when it supports troubleshoot by following the packet path layer by layer: resolve the name, identify addresses and routes, test ports and transport, validate TLS, then inspect HTTP behavior.

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